1. Field of Invention
Embodiments of the invention generally relate to archery equipment. More specifically, embodiments relate to apparatus, system and methods for establishing archery sight settings.
2. Discussion of Related Art
The field of archery involves the accurate placement of an arrow striking a target some distance from the point of release by the archer. The effect of gravity on the arrow's flight acts to draw the arrow back toward the ground as the arrow travels from the archer toward the target. To compensate for the effects of gravity, an archer holding a bow and aiming at a distant target, located at approximately the same elevation as the archer, will raise the bow such that the tip of the arrow is elevated above the rear of the arrow shaft. As a result, the arrow shaft is not located in a horizontal plane. Instead, the arrow has a pitch that is generally upward at a positive angle relative to the horizontal plane. During the subsequent shot, the arrow's flies in a parabolic trajectory, i.e., the arrow flies in an arc. The greater the shot-distance (distance between the archer and the target) the more pronounced the arc-of-flight. The arc-of-flight results in a constantly changing elevation as the arrow travels from the point of launch to the point of target impact.
In addition to gravity, the arrow's launch speed and drag also affect the amount of pitch that must be provided at launch to strike a point-of-aim on a target, because both the arrow's drag and its speed effect the time-of-flight from launch to impact. The greater the time-of-flight the more pronounced the arc-of-flight because an increased time-of-flight allows gravity to act on the arrow for a longer period of time. Thus, when comparing shots for different archery equipment, an arrow having a lower speed at launch and/or greater drag must be released at a greater pitch (relative to the horizontal plane) when compared with an arrow that leaves a bow at greater speed and/or has a lower drag.
An archer's understanding of the arrow's change in elevation over various distances is important to their success in both target archery and hunting. To-date, however, when setting archery sights in advance of shooting, archers have been forced to rely on trajectory estimates that are based only on an arrow's launch speed. Other approaches may also include theoretical affects based on the arrows weight as estimated by its length and mass/unit length (commonly expressed in grains/inch) or other physical characteristics. However, these approaches are inadequate because they do not account for the loss of speed in flight caused by the arrow's drag and/or they are difficult and tedious to complete. Further, differences in arrow drag are difficult to estimate and can only roughly approximate the effects on an arrow's trajectory. The preceding can result in significant differences in a point-of-impact on a target (i.e., decreasing accuracy), especially for longer distance shots.
Archery sights are affixed to an archery bow to allow the archer to precisely aim at a distant target. The sight includes at least one sight pin that is adjusted so that the archer can align it with a distant bullseye. As the distance to the target increases, a lower sight pin elevation is employed. This results in the archer raising the bow higher to align the sight pin with the bullseye as the shot-distance increases.
Archery sights fall into two general categories, single pin sights and multi-pin sights. Where a single pin sight is used the sight pin is temporarily locked in place when a shot is taken and the archer adjusts the elevation of the pin when the shot distance changes. In contrast, multi-pin sights generally include from 3-7 separate pins each used when shooting at a different known distance, respectively.
A sight-pin is sighted-in when an archer can place the sight pin over the center of the bullseye in their line-of-sight with the bow drawn, loose the arrow with the sight pin so located, and strike the center of the target. Because of the constantly changing elevation of an arrow in flight, the preceding result means that the sight-pin is sighted-in for the single shot-distance at which that particular shot or series of shots are taken.
Where a multi-pin sight is used an archer sights in each of the sight pins at a different known distance, respectively, and secures it in place. The sight pin for the closest of the selected distances is located at the highest elevation in the sight relative to the remaining sight pins. Conversely, the sight pin for the furthest of the selected distances is located at the lowest elevation in the sight relative to the remaining sight pins. Because a wide range of distance can be covered with a multi-pin sight, the sight pins typically are fixed in place via individual set screws. Accordingly, multi-pin sights are sometimes referred to as “fixed-pin” sights although they are adjustable at least during the sighting-in process. Once sighted in, the position of the sight pins is not adjusted unless something is changed with the archer, the bow or the arrow that affects arrow flight and trajectory.
Generally, single pin sights employ a sight tape that is affixed to the sight, for example, the sight-housing, and an alignment pin. The sight tape is marked with a series of marks for various shot-distances. The alignment pin provides the archer with a visual indication of the shot-distance that the sight pin is adjusted for. In some sights, the sight tape is stationary and the alignment pin moves with the sight pin as the elevation of the sight is adjusted. In other single pin sights, sight-adjustment moves the sight tape while the alignment pin remains stationary.
Today, manufacturers often provide a set of sight tapes and a marking tape for a given sight. To begin the sighting-in process, the archer places the marking tape on the sight and takes a shot or series of shots at a first known-distance to sight-in at that distance. In particular, a first known-distance that is marked on the tapes in the set of sight tapes. When the sight pin elevation is properly set for the first known-distance (the bow is sighted-in at the first distance), the archer marks the position of the alignment pin on the marking tape. The archer then takes a shot or series of shots at a second known-distance to sight-in at the second distance. The second known-distance is also a distance that is marked on the sight tapes. When the sight pin elevation is properly set for the second known-distance, the archer marks the position of the alignment pin on the marking tape. The sight tape is selected based on the distance separating the two marks on the marking tape, i.e., the gap between the two marks. Specifically, the archer compares the distance between the marks on the marking tape with the distance between the marks for the same two shot-distances on the tapes included in the set of sight tapes. The sight tape that is used is the sight tape that has a distance separating the marks for the first and second known-distances that most closely matches the distance established by the marking tape. In some approaches, a gauge is used to compare the gap on the marking tape with gaps provided on the various sight tapes in the set.
FIG. 5 illustrates a known process 160 for sight-tape selection. The process 160 requires that that the bow be sighted-in at a first distance and a second distance much farther downrange than the first distance. In particular, at act 162, the bow is sighted in at first distance (for example, 20 or 30 yards). The archer records the position of the sight pin for the first distance at act 163, for example by marking a blank set-up tape mounted on the archery sight. The process is then repeated at acts 164 and 165. For example, at act 164, the bow is sighted in at second distance (generally, 40 or more yards downrange). At act 165, the position of the sight pin for the second distance is recorded. At act 166, the sight tape for use across a range of distance from 20-80 yards downrange is selected from a set of sight tapes based on a difference between the sight pin position for the first distance and the sight pin position for the second distance.
Other manufacturers use a similar approach with a set-up tape that is pre-marked with indicia. A difference in value between a value of the numerical indicia adjacent the alignment pin when sighted-in at the first known-distance and a value of the numerical indicia adjacent to the alignment pin when sighted-in at the second known-distance is used to select the sight tape.
Depending on the type of structure employed to adjust the sight pin (for example, arms, levers, wheels, knobs and the like) the ratio of movement of the alignment pin relative to movement of the sight pin can vary. However, regardless of the specific means of adjustment, these approaches require accurate shooting to establish the sight-pin settings at the two known distances. Therefore, the difficulty with such approaches is the amount of time they require to complete and the fact that long distant shots must be used for at least one of the two known-distances. For example, a first shot-distance of 20 yards and a second distance of 50 yards are recommended in one approach while shot-distances of 30 and 60 yards are recommended in another approach. The long shot-distances of 50 and 60 yards are more difficult to sight-in because the group-size of a series of arrows shot at such distances are significantly larger on average than the group-size for shots taken at shorter distances. Therefore, it becomes more difficult for the archer to assess whether they are sighted-in with enough precision at that distance. Longer shot-distances not only make it difficult to accurately sight-in they also require more space than is typically available at indoor range facilities. Therefore, it can be difficult to locate a facility that allows the conventional sight-in procedure. In addition, it is easier to lose arrows outdoors at long shot-distances.
The preceding challenges also arise where a multi-pin sight is used because long distance shots must also be taken. Typically, for example, many archers take 20 yard shots to set the elevation for a 20 yard pin, 30 yard shots to set the elevation for a 30 yard pin, 40 yard shots to set the elevation for the 40 yard pin, 50 yard shots to set the elevation for the 50 yard pin, etc. Thus, the sight pin setting at 40, 50 or more yards results in the above drawbacks of shooting a long distance during the sight-in process.
Other archers use software to establish a series of pin gaps for a multi-pin sight. However, these software programs suffer from many of the same drawbacks because they also require that the archer sight-in at multiple distances including at least one distance of 50 yards or more. In addition, some of these approaches attempt to estimate a trajectory of an arrow based on the physical parameters of the arrow, i.e., how aerodynamic the arrow is. However, estimated arrow drag often results in an imprecise value. As a result, the pin gaps or sight tape settings are less precise than required.
Further, even where a pin gap for a multi-pin sight is known it must be transferred to the sight itself. However, current approaches are crude and lack precision. For example, one approach provides a pin-gapping printout printed using a thermal printer where the printout is based on arrow launch velocity. However, this approach is imprecise, is provided in a low resolution format and provides a result in a form that makes it difficult to directly transfer to an archery sight. Further, even the manner in which the indicia are provided can limit their effectiveness. For example, markings may include filled objects which are obscured by the actual pins or lack both horizontal and vertical lines used to identify the pin locations. In addition, the preceding approach requires access to a printer. As a result, the approach does not allow the user any mobility, for example, the ability to go to an outside archery range where electricity is unavailable and try the effects of various equipment adjustments on their sight settings.
These approaches are also tedious and inflexible because the user cannot easily determine how a change in one or more parameters (for example, overall arrow weight, arrow weight distribution sometimes referred to as front-of-center, arrow launch speed, arrow drag, etc.) effects the location of the sight marks relative to one another. In particular, the approach does not provide any ability to see the effects of changes in equipment performance on archery sight settings as the changes are made.
Thus, improvements in the approach for accurately determining an arrow's trajectory and establishing corresponding sight pin settings or other sight marks are necessary.
Electronic archery sights are known, for example, virtual archery sights located in a phone display where the phone is mounted to the bow. However, electronic archery sights are not legal in many states. Also, electronic sights can easily be damaged in the field by shock and/or moisture. They also require a power source that necessarily limits the amount of time the archer can spend in the field on a single charge. Once power is lost the sight becomes inoperative. Thus, improvements for establishing accurate sight marks for traditional archery sights are necessary.
Commonly-owned U.S. Pat. No. 8,221,273, entitled “APPARATUS, SYSTEM AND METHOD FOR ARCHERY EQUIPMENT,” issued on Jul. 17, 2012 (the '273 patent), generally describes a touchpad screen employed in an archery system. U.S. Pat. No. 8,221,273 is herein incorporated by reference in its entirety. However, neither the '273 patent nor any other prior approach describes how to utilize a portable electronic device with any style of display to generate a set of sight marks in a manner that allows the sight marks to be easily transferred from a graphical user interface to an archery sight, in particular, to an archery sight that includes one or more sight-pins whose location in the sight housing is mechanically adjusted.